Despite the DOJ’s decision, Kerry wrote in a letter March 26, "serious concerns" remain.

Kerry said that "to the extent that this merger would permit the only two entities authorized to provide satellite-radio service in the United States to merge, it would seem to directly contradict the intent of the commission in establishing this service."

Kerry added that the FCC should consider applying conditions to the merger, saying that "left unchecked, the entity that would emerge from this partnership would be capable of exercising monopolistic powers that could potentially result in diminished service at increased rates to consumers."

Kerry pointed out that he is a senior member of the Senate Commerce Committee -- which oversees the FCC along with the House Energy & Commerce Committee -- and said he will keep his eye on the FCC to make sure that it serves the public interest.